Diet Birch & Lichen?

[Arduska]

Hello! I have a Birch tree outside in my front yard. I was wondering if I could snap a few twigs & branches off and feed them to the guinea pigs. I've looked online and a lot of people say that the Birch is safe for piggies to eat, but I was wondering if it was safe for them to eat the lichen on them.

Thank you in advance!

 

[bpatters]

Neither would have been in a wild guinea pig's diet, and I wouldn't want to test them out on my guinea pigs.